JP2002278178A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an image forming device capable of reproducing a more faithful outputted image to inputted image data. SOLUTION: In this image forming device, the image is obtained by transferring and fixing a visible image on transfer material after performing image- exposure on an image carrier 6 by light beam scanning in accordance with the image data, forming a latent image and developing the latent image with toner in a developing device 8 so as to obtain a visible image. The device has a plurality of beams to reproduce resolution twice as high as the resolution of an optical scanning system by superposing two light beams and exposing with the light beams at the image exposure time by a writing part 4. The device is equipped with an optical detecting means for detecting the density of a toner image on the image carrier 6, and a reference toner image is formed on the image carrier, then the quantity of the respective light beams at image forming time is adjusted in accordance with the density of the reference toner image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital copying machine,
The present invention relates to an electrophotographic image forming apparatus such as a light beam printer, a light beam plotter, and a facsimile.

[0002]

2. Description of the Related Art Conventionally, a latent image is formed by exposing an image on an image carrier such as a photoreceptor by light beam scanning according to image data, and the latent image is developed with toner of a developing means to form a visible image. After that, the visible image is transferred to a transfer material such as recording paper, and an electrophotographic image forming apparatus that obtains an image by fixing is known, such as a digital copying machine, a light beam printer, a light beam plotter, It is applied to OA equipment such as facsimile.

In this type of image forming apparatus, Japanese Patent Application Laid-Open
In the prior art described in Japanese Patent Application Laid-Open No. 197776, there is a problem that an accurate image forming process is performed irrespective of machine differences, environment, and the like. A plurality of patterns are formed, and the relationship between the light intensity and the image edge position is determined from the average toner density for each pattern measured by the average density measurement means, and stored in the adjustment means. Then, when actually forming an image, by controlling the light beam amount based on this relationship, the image forming process can be performed irrespective of machine differences, environment, and the like.

The prior art described in Japanese Patent Application Laid-Open No. 10-181091 has a problem of forming an image with a resolution twice as high as that of a writing device having an optical scanning system. An image information source for supplying image data of twice the resolution, an image pattern determining means for determining a pattern in the sub-scanning direction of the image data input from the image information source, and a half of the image data according to the image pattern Exposure control means for outputting a light beam lighting signal and a light beam intensity signal to reproduce the image information with an optical scanning device having a resolution, and a light beam based on the light beam lighting signal and the light beam intensity signal from the exposure control means. By providing modulation exposure means for modulating, it is possible to form an image at twice the resolution of a writing device having an optical scanning system. .

[0005]

An optical scanning system has a plurality of light beams (a single scanning system may have a plurality of beams, or a single beam may have a plurality of scanning systems). ), When forming an image at twice the resolution of a writing device having the optical scanning system, "the toner images formed by each light beam alone must be equal" in order to accurately form the toner image. It is necessary that “a toner image formed by superimposing a plurality of light beams is equal to a toner image formed by each light beam alone”. In addition, since their balance varies depending on the machine difference, the aging environment, and the like, it is important to appropriately adjust the balance.

The present invention has been made in view of the above circumstances, and by appropriately adjusting the balance described above,
An object of the present invention is to provide an image forming apparatus capable of reproducing a more faithful output image with respect to input image data.

[0007]

According to a first aspect of the present invention, a latent image is formed by performing image exposure on an image carrier by light beam scanning according to image data. An image forming apparatus that develops an image into a visible image by developing the image with toner of a developing unit, transfers the visible image to a transfer material, and fixes the image to obtain an image. An image forming apparatus having a plurality of beams that reproduces a resolution twice as high as that of an optical scanning system by superposing and exposing a plurality of light beams, comprising an optical detecting unit for detecting a density of a toner image on the image carrier. A reference toner image is formed on the image carrier, and the amount of each light beam during image formation is adjusted in accordance with the density of the reference toner image.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the number of patterns of the reference toner image is at least “the number of beams + the number of beams of the optical scanning system”.
1 "pattern or more.
According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, at least “a pattern formed by each beam alone (total Beam) "and" one set of patterns formed by two adjacent beams (beam 1 and beam 2) ".

According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, at least a "pattern formed by only the beam 1" and a "beam 2" of the reference toner image in the case of a two-beam optical scanning system. Patterns formed only ",
The method is characterized in that the beam light amount at the time of image formation is adjusted using “a pattern formed by superimposing beam 1 and beam 2 and forming beams 1 and 2 in the sub-scanning direction”.

According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect, at least a "pattern formed by only the beam 1" and a "beam 2" of the reference toner image in the case of a four-beam optical scanning system. Patterns formed only ",
The adjustment of the beam light amount at the time of image formation using the “pattern formed only by the beam 3”, the “pattern formed only by the beam 4”, and the “pattern formed by superimposing the beam 1 and the beam 2”. It is a characteristic.

[0011]

(Embodiment 1) First, claims 1 to 1
Embodiment 4 of the invention will be described in detail with reference to the drawings. 1 to 5 show an embodiment of the invention according to claims 1 to 4. FIG. 1 is a schematic configuration diagram showing an example of the configuration of an image forming apparatus main body according to the present invention. In the figure, reference numeral 1 denotes an image forming apparatus main body, and 2 denotes an automatic document feeder (AD) for automatically feeding a document.
F) 3 is a scanner unit for reading an image of the document fed on the contact glass by the ADF, and 4 is an exposure scan of the image carrier 6 with a light beam such as a laser beam based on the image data read by the scanner unit. A writing unit for writing an image, and a drum unit 5 for housing an image carrier 6, an image carrier (photosensitive drum) 6 composed of a drum-shaped photoconductive photoconductor, and a reference numeral 7 installed on the drum unit 5. A charging unit (corona charger, charging roller, charging brush, solid charger, etc.) for charging 6, and a developing unit (one component) that is mounted on the drum unit 5 and develops a latent image formed on the image carrier 6 with toner A developing unit using a system developer (toner) or a two-component system developer (toner and carrier), and a transfer unit 9 installed below the drum unit 5 for transferring a toner image on an image carrier to a transfer material In the example shown in the figure, a belt transfer device using a transfer belt), a cleaning unit (cleaning device using a cleaning blade, a cleaning brush, or the like) installed on the drum unit 5 for removing transfer residual toner on the image carrier, and 11 A fixing unit (a fixing device using a heating roller and a pressure roller, etc.) for fixing the toner image transferred onto the transfer material by heating and / or pressing; A reversing / discharging unit 13 for distributing to a paper discharging unit; 13 is a double-sided unit for reversing and feeding a transfer material when forming a double-sided image; 14 is storing and transferring a large amount of frequently used recording material such as recording paper. A tandem LCT 15 for feeding the recording material such as recording paper of various sizes and a universal tray for feeding the recording material and the like to the transfer portion 16 are provided to the developing portion 8. Toner bank to accommodate the over (toner bottle), 17 waste toner bottle for storing the waste toner collected by the cleaning unit 10,
An operation unit 18 for performing various settings of the image forming apparatus;
Reference numeral 19 denotes an operation panel (such as a touch panel) which also serves as a display unit of the operation unit.

In FIG. 1, when an image forming operation is started, an image of a document fed by the ADF 2 is read by a scanner unit 3 and the image data is transmitted to a writing unit 4. In parallel with this, the image carrier 6 of the drum unit 5 is uniformly charged by the charging unit 7, and thereafter, the light beam corresponding to the image data is exposed from the writing unit 4 to form an electrostatic latent image on the image carrier. Is formed. Next, the electrostatic latent image on the image carrier 6 is developed with a toner in a developing unit 8 to be a visible image (toner image), and this toner image is transferred from the image carrier in the transfer unit 9 to a recording paper or the like. It is transferred onto a transfer material. Thereafter, the transfer material onto which the toner image has been transferred is sent to the fixing unit 11, where the toner image is fixed on the transfer material. The image forming apparatus shown in FIG. 1 includes a photo sensor (not shown) downstream of the developing unit in the drum unit 5 in the image carrier rotation direction, and optically reflects the reference toner image formed on the image carrier 6. The concentration can be measured.

FIG. 2 is a schematic perspective view showing a main configuration of a light beam scanning type writing unit constituting the writing section 4 of the image forming apparatus of FIG. The writing unit 4 is configured to write a latent image on the photosensitive drum 6 serving as an image carrier using an optical scanning system that deflects and scans a light beam using an optical deflector 32. An LD unit using a laser diode (LD) as a light source for the light beam, a cylinder lens 22 for condensing the light beam from the LD unit in the sub-scanning direction, and a first 23 for bending the optical path of the light beam passing through the cylinder lens Mirror 24 is a polygon mirror that deflects and reflects the light beam
And a light deflector comprising a polygon motor for rotationally driving the rotary polygon mirror. The first and second light deflectors 25 and 26 collect light beams deflected and scanned by the light deflector and form an image on a photosensitive drum surface. Lens 27, a barrel-shaped toroidal lens (BTL) 27 for correcting curvature of field, aberration and the like, and 28 and 29 for bending the optical path of the light beam after passing through the BTL.
, 30 is a synchronization detection mirror, 31 is a synchronization detection sensor, 32 is a polygon motor driver that controls the driving of the polygon motor, 33 is a cooling intake fan, 34 is a dustproof filter, 35 is an exhaust fan, and 36 is dustproof. It is glass. FIG. 3 shows the LD of the writing unit 4 shown in FIG.
FIG. 3 is a diagram illustrating a configuration example of a unit 21. The LD unit 21 includes an LD light source unit 37, a collimating lens 38, and an aperture 39. In the LD light source unit 37, two laser light emitters (LD1, LD2) are provided. Consisting of 2
Channel laser diode array (2-channel L
D array) 37a and photodiode 37 for detecting the amount of light
b is housed, and two light beams (laser beams) can be emitted from the LD array 37a.

FIG. 4 is a block diagram showing an example of a control system for controlling the driving of the LD array by processing the image data of the original read by the scanner unit 3 and inputting the processed image data to the LD driver of the LD unit of the writing unit. It is. 4, a scanner unit 3 includes, for example, a contact glass 3-1 on which a document 41 is placed, a light source 3-2, and mirrors 3-3 to 3-3.
-5, imaging lens 3-6, solid-state imaging device (CCD) 3-
7 irradiates the original on the contact glass 3-1 with light from the light source 3-2, and reflects the reflected light image from the original 41 on the mirrors 3-3 to 3-5 and the imaging lens 3-6. Via C
An image is formed on a CD 3-7, photoelectrically converted by a CCD 3-7, and output. The output signal from the CCD 3-7 is SBU (Sens
or Board Unit) 42, amplifies and A / D-converts, and as image data, an SICU (Scan)
ner & image processing control unit) 43. SICU43 is for image compression / decompression, memory / HD
MSU (Memory Superchar) with D controller function
ger Unit) 44 and an IPU (Image Proc) that performs image processing
essing unit) 45, performs image processing on image data input from the SBU 42, and generates an LDB (Leser diode Driving).
e Board) 52. The LDB 52 is an LD drive board for controlling the driving of the LD array 37a of the LD unit 21 shown in FIGS. 2 and 3, and includes an LD controller 46 for controlling the driving of the LD according to the image data from the IPU 45, and a pulse width modulation. (PWM (Pulse Width Modula
) and power modulation (PM (Power Modulation)), and an LDD for controlling lighting of the LD
(Leser Diode Drive) 49, 50 and L shown in FIG.
A two-channel LD array (LDA) including two laser emitters corresponding to the LD array 37a of the D unit 21
(Leser Diode Alley) 51. In this control system, a latent image is formed on the image carrier (photosensitive drum) 6 at a resolution twice as high as that of the input image data by superimposing light beams from the LDs adjacent to the LD array 51 (37a). .

Next, FIG. 5 shows a two-channel LD array 51 (3) for forming a reference toner image to be used when adjusting the light quantity in the image forming apparatus having the structure shown in FIGS.
7A is a diagram showing a model of an exposure pattern by light beams from two LDs (LD1, LD2) of FIG. 7A, wherein FIG. 7A shows an exposure pattern of only the light beam from LD1, and FIG.
(C) shows an exposure pattern in which light beams from two adjacent LDs (LD1 and LD2) are superimposed, and (d) shows an exposure area where a toner image is formed. Is shown as an example.

As in the model shown in FIG. 5, before forming an image in advance, it is determined which profile of the input image data should be used to form an electrostatic latent image with LD light. At the time of actual image formation, an electrostatic latent image is formed based on the information (tuning data). FIG.
As shown in (d), a region where a toner image is formed on the photosensitive drum 6 at a position and size that can be read by a photo sensor (not shown) in the drum unit 5 is formed as a line image (halftone) or the like. In this case, first, a reference toner image is formed by an exposure pattern of only the LD 1 as shown in FIG. Then, the optical density is measured by a photo sensor, and feedback is performed so as to obtain an appropriate density, and the LD light amount (PM) is adjusted (a plurality is formed and adjusted as necessary). Next, as shown in FIG.
Forming a reference toner image with an exposure pattern of only D2,
Similarly, the LD light amount is adjusted. Thereby, LD1 and L
The light amount of D2 and its balance are taken. Finally, FIG.
As shown in (c), a reference toner image is formed by an exposure pattern in which the light beams of LD1 and LD2 are superimposed, and the LD light amount (P
Adjust M).

As a result, the LD for the image data is
1. The image bearing member (photosensitive drum) 6 is adjusted by adjusting the balance and light amount of the LD 2 and the superposition of the LD 2 with time and environment.
And reproduces an output image that is more faithful to the input image data.
The pattern of the superposition may be a pattern formed by a set of LD2 and LD1 instead of the set of LD1 and LD2, or may be performed by both (only the LD1 and only the LD2 are superposed). If one of the two patterns matches, all four writing patterns should match, but adjustment may be made for all four patterns to increase accuracy.) Similarly, if a plurality of image data (for example, image data with a changed line width) are adjusted and an image is formed based on the data (adjustment value), a more faithful output image can be reproduced. Can be.

(Embodiment 2) Next, an embodiment of the invention according to claims 1 and 5 will be described. 1, 2 and 6 to 8 show an embodiment of the invention according to the first and fifth aspects. FIG. 1 is a schematic configuration diagram showing one configuration example of an image forming apparatus main body according to the present invention, and FIG. 2 is a perspective view showing a main configuration of a writing unit. These configurations and operations have already been described in the first embodiment. Since it has been described, the description is omitted here. FIG. 6 is a diagram illustrating another configuration example of the LD unit of the writing unit 4 illustrated in FIG. 2. The LD unit 21 includes an LD light source unit 40, a collimating lens 38, and an aperture 39.
In the LD light source unit 40, four laser light emitters (LD1, LD1,
LD2, LD3, LD4) 4 channel laser diode array (4 channel LD array) 40a
And a photodiode 40b are housed therein so that four light beams (laser beams) can be emitted from the LD array 40a.

FIG. 7 is a block diagram showing an example of a control system for processing image data of a document read by the scanner unit 3, inputting the processed image data to the LD driver of the LD unit 21, and controlling the driving of the LD array 40a. is there. 7, a scanner unit 3 includes, for example, a contact glass 3-1 on which a document 41 is placed, a light source 3-2, and mirrors 3-3 to 3-3.
5, imaging lens 3-6, solid-state imaging device (CCD) 3-7
And irradiates the original on the contact glass 3-1 with light from the light source 3-2, and reflects the reflected light image from the original 41 via the mirrors 3-3 to 3-5 and the imaging lens 3-6. CC
An image is formed on D3-7, photoelectrically converted by CCD3-7 and output. The output signal from the CCD 3-7 is SBU (Sensor
Board Unit) 42, amplifies and A / D-converts, and as image data, an SICU (Scanne
r & image processing control unit) 43. SICU43 is for image compression / decompression, memory / HDD
MSU (Memory Supercharge) with controller function
r Unit) 44 and an IPU (Image Proces) for performing image processing.
sing unit) 45, performs image processing on image data input from the SBU 42, and generates an LDB (Leser diode Drive).
Board) 53. The LDB 53 is an LD drive board for controlling the driving of the LD array 40 a of the LD unit 21 shown in FIGS. 2 and 6, and the LD controller 5 for controlling the driving of the LD according to the image data from the IPU 45.
4 and Pulse Width Modulation (PWM)
n)) and modulating units 55, 56, 57, 58 for performing power modulation (PM), and LDDs (Leser Diode Drives) 59, 60, 61, for controlling the lighting of the LD.
62 and the LD array 4 of the LD unit 21 shown in FIG.
A four-channel LD array (LDA (Leser Diode Alley)) 63 including four laser light emitters corresponding to Oa is provided. In this control system, the LD array 63 (40
The light beams from the adjacent LDs are superimposed in a) to form a latent image on the image carrier (photosensitive drum) 6 at twice the resolution of the input image data.

Next, FIGS. 8 and 9 show four Ls of an LD array for forming a reference toner image used for adjusting the amount of light in an image forming apparatus having the structure shown in FIGS.
FIG. 8 is a diagram showing a model of an exposure pattern by a light beam from D (LD1, LD2, LD3, LD4);
8A is an exposure pattern of only the light beam from LD1, FIG. 8B is an exposure pattern of only the light beam from LD2,
8C shows an exposure pattern of only the light beam from LD3, FIG. 9A shows an exposure pattern of only the light beam from LD4, and FIG. 9B shows two adjacent LDs (LD1, LD1).
2 shows an exposure pattern in which the light beams from 2) are superimposed.

As shown in FIGS. 8 and 9, what profile should be used to form an electrostatic latent image with LD light on input image data before image formation is performed in advance. When an image is actually formed, an electrostatic latent image is formed based on the information (tuning data). As in FIG. 5D, a region where a toner image is formed on the photosensitive drum 6 in a position readable by a photo sensor (not shown) in the drum unit 5 and a size is a line image (halftone) or the like. At this time, first, as shown in FIG. 8A, a reference toner image based on the exposure pattern of only the LD 1 is formed. Then, the optical density is measured by a photo sensor, and feedback is performed so as to obtain an appropriate density, and the LD light amount (PM) is adjusted (a plurality is formed and adjusted as necessary). Next, as shown in FIG. 8B, a reference toner image is formed based on the exposure pattern of only the LD2, and the amount of LD light is similarly adjusted. Next, as shown in FIG. 8C, a reference toner image is formed based on the exposure pattern of only the LD 3, and the amount of LD light is similarly adjusted. Next, FIG.
The reference toner image is formed by the exposure pattern of only the LD 4 as described above, and the LD light amount is adjusted similarly. Thereby, the light amounts of the LDs 1 to 4 and the balance thereof are obtained. Finally, as shown in FIG. 9B, a reference toner image is formed by an exposure pattern in which the light beams of LD1 and LD2 are superimposed, and the LD light amount (PM) at the time of superimposition is similarly adjusted so as to obtain an appropriate density. I do.

Thus, the LD for the image data is
1, LD2, LD3, LD4 and superimposed (LD1 and LD
2) The balance of 5 and the amount of light are optimized to respond to changes in the sensitivity and development characteristics of the image carrier (photosensitive drum) 6 due to aging, environment, etc. Reproduce a faithful output image. Note that the overlapping pattern is not a set of LD1 and LD2, but an LD.
2 and LD3, LD3 and LD4, or LD
4 and LD1 may be used.
Further, it may be performed for all of the above four patterns (LD1
If only one of the four superimposed patterns, LD2 only, LD3 only, LD4 only, matches one of the eight writing patterns, then all eight writing patterns should match, but adjustment is made for all eight patterns to increase the accuracy. May be). Similarly, if a plurality of image data (for example, line width) are adjusted and an image is formed based on the data (adjustment value), a more faithful output image can be reproduced.

[0023]

As described above, the image forming apparatus according to the first aspect includes the optical detecting means for detecting the density of the toner image on the image carrier, and the reference toner image is provided on the image carrier. Is formed, and the respective light beam light amounts at the time of image formation are adjusted in accordance with the density of the reference toner image, so that a more faithful output image can be reproduced with respect to the input image data.

In the image forming apparatus according to the second aspect,
In addition to the configuration of claim 1, the number of patterns of the reference toner image is at least “the number of beams + 1” or more patterns with respect to the number of beams of the optical scanning system. Output image can be reproduced. In the image forming apparatus according to the third aspect, in addition to the configuration of the first aspect, as a combination of the pattern of the reference toner image, at least the number of beams of the optical scanning system is
"Pattern formed by each beam alone (all beams)",
Since "a set of patterns formed by two adjacent beams" is included, a more faithful output image can be reproduced with respect to the input image data.

In the image forming apparatus according to the fourth aspect,
In addition to the configuration of claim 1, a reference toner image in the case of a two-beam optical scanning system is at least a "pattern formed by beam 1 only", a "pattern formed by beam 2 only", and "beam 1 and beam". 2 is superposed and the pattern is formed in the order of the beams 1 and 2 in the sub-scanning direction ", the beam light amount is adjusted at the time of image formation, so that more faithful to the input image data. The output image can be reproduced.

In the image forming apparatus according to the fifth aspect,
In addition to the configuration of claim 1, the reference toner image in the case of a four-beam optical scanning system is at least a "pattern formed only by beam 1", a "pattern formed only by beam 2", and a "pattern formed only by beam 3". The beam light quantity at the time of image formation is adjusted using the “pattern to be formed”, “pattern to be formed only by beam 4”, and “pattern to be formed by superimposing beams 1 and 2”. On the other hand, a more faithful output image can be reproduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a configuration example of an image forming apparatus according to the present invention.

FIG. 2 is a schematic perspective view showing a main configuration of a writing unit constituting a writing unit of the image forming apparatus shown in FIG.

FIG. 3 is a diagram illustrating a configuration example of an LD unit of the writing unit illustrated in FIG. 2;

FIG. 4 is a block diagram illustrating an example of a control system that processes image data of a document read by a scanner unit, inputs the processed image data to an LD driver of an LD unit, and controls driving of a two-beam LD array.

FIG. 5 shows an image forming apparatus having the configuration shown in FIGS.
FIG. 7 is a diagram illustrating a model of an exposure pattern by light beams from two LDs (LD1 and LD2) of an LD array when forming a reference toner image used at the time of adjusting a beam light amount;
(A) is a diagram showing an exposure pattern of only the light beam from LD1, (b) is a diagram showing an exposure pattern of only the light beam from LD2, and (c) is a diagram showing two adjacent LDs (LD1, LD1).
FIG. 4D is a diagram illustrating an exposure pattern in which the light beams from D2) are superimposed, and FIG. 4D is a diagram illustrating an example of an exposure region on the photosensitive drum where a toner image is formed.

FIG. 6 is a diagram illustrating another configuration example of the LD unit of the writing unit illustrated in FIG. 2;

FIG. 7 is a block diagram illustrating an example of a control system that performs image processing on image data of a document read by a scanner unit, inputs the processed image data to an LD driver of an LD unit, and controls driving of a 4-beam LD array.

FIG. 8 shows four LDs (LD1, LD1) of an LD array when an image forming apparatus having the configuration shown in FIGS.
FIGS. 2A and 2B are diagrams showing a model of an exposure pattern by a light beam from LD2, LD4), wherein FIG. 2A shows an exposure pattern of only a light beam from LD1, and FIG. The figure which shows a pattern, (c) is LD
FIG. 9 is a view showing an exposure pattern of only the light beam from No. 3;

FIG. 9 shows four LDs (LD1, LD1) of an LD array when an image forming apparatus having the configuration of FIGS.
2A and 2B are diagrams illustrating a model of an exposure pattern by a light beam from LD3, LD4), wherein FIG. 2A is a diagram illustrating an exposure pattern only by a light beam from LD4, and FIG.
FIG. 4 is a diagram showing an exposure pattern in which light beams from two LDs (LD1, LD2) are superimposed.

[Explanation of symbols]

 1: Image forming apparatus main body 2: Automatic document feeder (ADF) 3: Scanner section 4: Writing section 5: Drum unit 6: Image carrier (photosensitive drum) 7: Charging section 8: Developing section 9: Transfer section 10 : Cleaning unit 11: Fixing unit 12: Reversal / discharge unit 13: Double-sided unit 14: Tandem LCT 15: Universal tray 16: Toner bank (toner bottle) 17: Waste toner bottle 18: Operation unit 19: Operation panel 21: LD Unit 22: Cylinder lens 23: First mirror 24: Optical deflector 25: First fθ lens 26: Second fθ lens 27: Barrel toroidal lens (BTL) 28: Second mirror 29: Third mirror 30: Mirror for synchronization detection 31: Synchronous detection sensor 32: Polygon motor driver 33: Intake fan 34: Dustproof filter 35: Exhaust fan 36: Dust Glass 37: LD light source unit 37a: 2-channel LD array 37b: photodiode 38: collimating lens 39: aperture 40: LD light source unit 40a: 4 channels LD arrays

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Saito 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. (72) Inventor Yuji Suzuki 1-3-6 Nakamagome, Ota-ku, Tokyo・ F-term in Ricoh Co., Ltd. (Reference) 2C362 AA12 AA53 AA54 AA66 BA63 BA64 BA67 CB05 CB08 2H027 DA10 DE02 EA02 EC03 2H076 AB06 AB12 DA07 DA17 5C074 AA07 BB02 BB03 BB26 CC26 DD08 DD14 EE11 GG02 GG09 GG09GG12GG

Claims (5)

[Claims] An image exposure is performed on an image carrier by light beam scanning according to image data to form a latent image, and the latent image is developed by a toner of a developing means to become a visible image. An image forming apparatus for transferring a visual image to a transfer material and fixing the image to obtain an image, wherein at the time of the image exposure, two light beams are overlapped and exposed to thereby achieve a resolution twice as high as that of an optical scanning system. An image forming apparatus having a plurality of beams to be reproduced, comprising: an optical detection unit configured to detect a density of a toner image on the image carrier, forming a reference toner image on the image carrier, and An image forming apparatus, wherein each light beam amount at the time of image formation is adjusted according to the density. 2. The image forming apparatus according to claim 1, wherein the number of patterns of the reference toner image is at least “the number of beams + 1” or more with respect to the number of beams of the optical scanning system. apparatus. 3. The image forming apparatus according to claim 1, wherein at least “a pattern formed by each beam alone (all beams)”, “ An image forming apparatus, comprising: "a set of patterns (beam 1 and beam 2) formed by two adjacent beams". 4. The image forming apparatus according to claim 1, wherein the reference toner image in the case of a two-beam optical scanning system is at least a “pattern formed only by the beam 1” and a “pattern formed only by the beam 2”. An image forming apparatus which adjusts the amount of beam at the time of image formation using "a pattern formed by superimposing beam 1 and beam 2 and forming beams 1 and 2 in the sub-scanning direction" in that order. . 5. The image forming apparatus according to claim 1, wherein the reference toner image in the case of a four-beam optical scanning system is at least a “pattern formed only by the beam 1” and a “pattern formed only by the beam 2”. , “Pattern formed only by beam 3”, “pattern formed only by beam 4”,
"Pattern formed by superimposing beam 1 and beam 2"
An image forming apparatus for adjusting the amount of light beam during image formation using the image forming apparatus.